Sadly, BvS doesn't stand up to much scrutiny on repeat viewings. After a second watch, I understand the philosophy underpinning the narrative. It's wholly surmised with this line:

"That's how it starts. The fever, the rage, the feeling of powerlessness that turns good men... cruel."- Alfred Pennyworth

This is all the movie needed to be. It's a simplistic notion that immediately has pathos and is the motivational catalyst for every central character...until it is lost in poorly theorised theological parallels…